title: MiR-133a modulates osteogenic differentiation of vascular smooth muscle cells.
abstract: Arterial calcification is a key pathologic component of vascular diseases such as atherosclerosis, coronary artery disease, and peripheral vascular disease. A hallmark of this pathological process is the phenotypic transition of vascular smooth muscle cells (VSMCs) to osteoblast-like cells. Several studies have demonstrated that microRNAs (miRNAs) regulate osteoblast differentiation, but it is unclear whether miRNAs also regulate VSMC-mediated arterial calcification. In the present study, we sought to characterize the role of miR-133a in regulating VSMC-mediated arterial calcification. Northern blotting analysis of VSMCs treated with β-glycerophosphate demonstrated that miR-133a was significantly decreased during osteogenic differentiation. Overexpression of miR-133a inhibited VSMC transdifferentiation into osteoblast-like cells as evidenced by a decrease in alkaline phosphatase activity, osteocalcin secretion, Runx2 expression, and mineralized nodule formation. Conversely, the knockdown of miR-133a using an miR-133a inhibitor promoted osteogenic differentiation of VSMCs by increasing alkaline phosphatase activity, osteocalcin secretion, and Runx2 expression. Runx2 was identified as a direct target of miR-133a by a cotransfection experiment in VSMCs with luciferase reporter plasmids containing wild-type or mutant 3'-untranslated region sequences of Runx2. Furthermore, the pro-osteogenic effects of miR-133a inhibitor were abrogated in Runx2-knockdown cells, and the inhibition of osteogenic differentiation by pre-miR-133a was reversed by overexpression of Runx2, providing functional evidence that the effects of miR-133a in osteogenic differentiation were mediated by targeting Runx2. These results demonstrate that miR-133a is a key negative regulator of the osteogenic differentiation of VSMCs.
authors.affiliation: Departments of Cardiothoracic Surgery, The Second Xiangya Hospital of Central South University, Changsha, 410011, People’s Republic of China.
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Liao
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Zhang
authors.forename: Ke
authors.initials: K
authors.lastname: Yuan
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiang
authors.initials: X
authors.lastname: Feng
authors.forename: Rong-Rong
authors.initials: RR
authors.lastname: Cui
authors.forename: Ye-Rong
authors.initials: YR
authors.lastname: Hu
authors.forename: Zhao-Shun
authors.initials: ZS
authors.lastname: Yuan
authors.forename: Lu
authors.initials: L
authors.lastname: Gu
authors.forename: Shi-Jun
authors.initials: SJ
authors.lastname: Li
authors.forename: Ding-An
authors.initials: DA
authors.lastname: Mao
authors.forename: Qiong
authors.initials: Q
authors.lastname: Lu
authors.forename: Xin-Ming
authors.initials: XM
authors.lastname: Zhou
authors.forename: Vinicio A
authors.initials: VA
authors.lastname: de Jesus Perez
authors.forename: Ling-Qing
authors.initials: LQ
authors.lastname: Yuan
mesh_terms: D020413:3' Untranslated Regions / Q000187:drug effects; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D054338:Cell Transdifferentiation / Q000187:drug effects; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D005260:Female; D020868:Gene Silencing; D017930:Genes, Reporter / Q000187:drug effects; D005994:Glycerophosphates / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D009154:Mutation; D016376:Oligonucleotides, Antisense / Q000009:adverse effects; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D015675:Osteocalcin / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism; D061205:Vascular Calcification / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control
chemical_list: D020413:3' Untranslated Regions; D015415:Biomarkers; D050659:Core Binding Factor Alpha 1 Subunit; D005994:Glycerophosphates; D035683:MicroRNAs; C517732:Mirn133 microRNA, mouse; D016376:Oligonucleotides, Antisense; D011994:Recombinant Proteins; C493716:Runx2 protein, mouse; D015675:Osteocalcin; C031463:beta-glycerophosphoric acid